The invention relates to a system comprising a processing or work table over which a boom can move. The boom supports a head equipped with one or more tools. In a preferred application, the head is equipped with one or more cutting tools.
The invention also relates to a safety system, in particular of the type intended for work tables, for example cutting tables.
The invention applies to cutting machines and to machines for processing sheet materials, in particular labeling systems or machines for printing sheet materials.
Cutting tables are used to cut flexible materials, for example textile materials, using a penetrating blade or laser beams, for example.
They are more particularly intended for use in the furnishing or tailoring industries, especially in prototyping and making-to-measure, and for use in some applications for cutting technical fabric.
FIGS. 1A and 1B show one example of a cutting table.
The cutting table includes a table 2 generally comprising cutting supports 17, 19 fixed or stuck to boxes 18, 20 (FIG. 1B). The boxes are isolated from each other and supported on a system of legs 4-1, 4-2, 4-3 (FIG. 1A) and stringers (not shown in the figures).
A suction system is fixed under each box. These cutting support plates are hard and porous.
The tops of the boxes, on which the cutting plates rest, are perforated. The suction system therefore holds down the material through the boxes and the cutting plates.
Two rails 8 and 10 are fixed to the boxes 18 and 20 on respective opposite sides of the table and guide a moving boom 22 as it moves in either direction along the longitudinal axis X of the table between a front area 12 and a rear area 14 of the table.
The boom 22 is equipped with a cutting head 30 mounted on a carriage 35 movable along the boom in a direction Y substantially perpendicular to the direction of the axis X. The cutting head is equipped with a cutting blade 32 for cutting out required shapes from a flexible material, for example a textile material, placed on the table.
A control console 34 generally including a microcomputer (PC) controls the starting of cutting and movements of both the boom 22 and the cutting head 30 to produce pieces from the flexible material. An operator controls the system by means of a keyboard and a display screen which enable the operator to display the lay out of parts to be produced from sheets of flexible material.
This kind of cutting system is accessible from both sides, as well as from the front and the rear of the table, to enable maintenance operations, bringing up and loading a flexible material, offloading pieces cut out from the material, and monitoring cutting.
This kind of cutting table is generally relatively long, for example from 3 to 18 meters long.
Thus an operator 16 generally monitors cutting by moving around the table. Movement of the boom 22 along the axis X can impact laterally on the operator. This raises a problem of safety in the working and maintenance area around the cutting machine.
A first solution to this problem consists of equipping the moving boom with lateral safety bars 40, 42 which are moving relative to the support carriages 31, 33 at the ends of the boom.
FIG. 2 shows in more detail the mounting of a protection bar 40 on its carriage 31. The bar passes through guide members 53, 57 fixed to the carriage 31. An electromechanical sensor 41 is also fixed to the carriage 31. One end of the sensor locates in a notch 39 in the bar 40. The bar 40 is moved relative to the carriage 31 when it encounters an obstacle during movement of the boom 22 along the X axis.
The end of the sensor 41 then leaves the notch 39, which trips a switch and cuts off the power supply to the drive system of the boom 22.
Although that kind of system is satisfactory in some respects, it does not address a number of problems. The problem therefore arises of proposing a safer cutting system.
In particular, the above type of system cannot detect the presence of an operator""s arm or hand above one end of the boom 22. The operator can be sufficiently far away from the cutting table for the lateral bars on his side of the table not to strike him, in which case the safety system is not tripped, but nevertheless the operator can have a hand or an arm positioned above the end of the boom.
What is more, the above type of prior art system cannot detect an obstacle near the boom.
An obstacle near the boom could be on the surface of the cutting table, for example a foreign body which could form a dangerous projectile if struck by the boom and/or the cutting head.
An obstacle near the boom could equally well be above the surface of the cutting table, for example an operator""s hand approaching the boom 22 or the support 35.
For the above reasons the invention provides a moving assembly for a system for working or processing flexible materials, especially materials used in tailoring, or textile materials, the assembly comprising:
a boom extending along an axis between first and second ends and a working head mounted on said boom;
first and second lateral obstacle sensor systems mounted at each end of the boom, movable or deformable relative to the boom and independently of each other in a direction (X) substantially perpendicular to the axis of the boom, and having an extension in the same direction on either side of the boom; and
respective first and second optical systems fixed to the first and second lateral obstacle sensor systems to detect the presence of an obstacle on the path of the boom and movement and/or deformation of the lateral obstacle sensor systems relative to each other.
Lateral obstacles, or an obstacle on the path of the moving boom, are therefore detected optically.
The optical system preferably comprises one or more pairs of emitters and sensors, with each emitter mounted on one of the lateral obstacle sensor systems and the corresponding sensor mounted on the other lateral obstacle sensor system.
In one variant, the first optical system comprises an emitter-receiver pair mounted on one of the lateral obstacle sensor systems and the second optical system comprises a system mounted on the other lateral obstacle sensor system to reflect a beam emitted by the emitter towards the receiver.
Optical systems for detecting obstacles on the path of the boom can additionally be mounted on the boom, and rigidly or deformably connected to it.
The optical systems mounted on the boom and fixed relative to the lateral obstacle sensor systems then define a safety volume around the boom.
The first and second lateral obstacle sensor systems may be movable independently of each other relative to the boom, in a direction substantially perpendicular to the axis of the boom, with an extension in the same direction on either side of the boom.
Respective first and second movement sensor systems, for example electromechanical sensors, may be associated with the first and second lateral obstacle sensor systems.
The optical systems mounted on the lateral obstacle sensor systems then constitute a second level of safety measures in the event non-operation of the movement sensor system associated with the first and/or second lateral obstacle sensor system in response to detection of a lateral obstacle.
In another embodiment, the first and second lateral obstacle sensor systems comprise at least one support that can be deformable in a direction perpendicular to the axis of the boom and is mounted on the first and/or second lateral obstacle sensor system.
Furthermore, optical systems can be fixed to the deformable support to detect obstacles on the path of the boom and to detect deformation of the deformable support in said direction perpendicular to the axis of the boom.
In another embodiment, the first and/or the second lateral obstacle sensor system has a first part movable in said direction substantially perpendicular to the axis of the boom and a second part articulated to the first part and able to rotate about an axis substantially perpendicular to said direction, and either the first optical system or the second optical system is fixed to this second part.
In another aspect, the first lateral obstacle sensor system has first and second parts movable relative to each other and each part is provided with an optical system for detecting the presence of an obstacle on the path of the boom and movement of one of the lateral obstacle sensor systems relative to the other one.
The second lateral obstacle sensor system may additionally have third and fourth parts movable relative to each other, with each part provided with an optical system for detecting the presence of an obstacle on the path of the boom and movement of one of the lateral obstacle sensor systems relative to the other one.
An optical element is advantageously disposed on an optical path defined between the first and second lateral obstacle sensor systems. This optical element is additionally connected to the cutting head and its position relative to the latter changes if it encounters an obstacle during movement of the boom and the cutting head.
In a further aspect, the cutting head includes a protective cover that protects it when closed and which intercepts an optical path defined between the first and second fixed optical systems on the first and second lateral obstacle sensor systems.
The invention also provides a system for processing flexible materials, the system comprising:
a work support or table;
one or more moving assemblies as described hereinabove; and
a system for moving said moving assembly or assemblies on the work support or table.
The moving assembly, with its safety systems, is suitable for work tables whose width is from 0.3 meters (m) to 5 m, for example, and for a maximum speed of the boom from 0 to 3 meters per second (m/s) (180 m/min), for example.
The work table can be fixed or moving, in the latter case incorporating a conveyor.
The working head supports a cutting tool and/or a printing tool and/or a labeling tool and/or a perforation tool, for example.